This invention relates generally to control valves utilized in energy conservation systems and more particularly to a thermally actuated phase change operated control valve for use in an energy conservation system for recovering heat from the refrigerant to water heat exchanger in a refrigeration cycle for an air conditioning system.
It is a known practice to heat water by reclaiming heat from the high temperature discharge gases of the compressor in a refrigeration cycle. In many instances this rejected heat is disposed to waste. However, the concept of reclaiming heat from the high temperature discharge gases of a compressor in a refrigeration cycle is particularly applicable to an air conditioning system where the refrigeration cycles operate at somewhat higher temperature and pressure levels because such reclaimed heat can be applied to usable purposes.
By removing heat from the high temperature discharge gases of the compressor in the refrigeration cycle or heat pump cycles of an air conditioning system before these gases are passed to a conventional condensing stage in such air conditioning systems, substantial heat recovery can be effected in a range from 4500 to 5500 BTU/hr per ton of unit capacity.
This is accomplished by inserting a suitable refrigerant-to-water heat exchanger between the compressor discharge and the inlet to the condensor in such air conditioning systems.
In effect condensing is accomplished in two steps. First, the desuperheating step where substantial quantities of heat are reclaimed and then the condensing step where the cooled gases are subjected to the conventional condensing for the refrigerant cycle.
Such an arrangement must of course be optimized by properly sizing the heat exchanger to provide the proper heat transfer capacity so that the heat is recovered without effecting the operation of the refrigeration cycle for the air conditioning system. If the heat exchanger is sized too large, the high temperature discharge gases from the compressor will condense to refrigerant liquid in the desuperheating step which will result in reduced head pressures, thus reducing capillary tube or expansion valve capacities and performance of the refrigeration cycle for the air conditioning system.
In the present invention a temperature actuated phase change operated control valve is provided for use in an improved circulating water system adapted for the recovery of waste heat by operative association with a waste heat source such as a refrigerant-to-water heat exchanger for the desuperheating of the high temperature discharge gases of the refrigerant cycle for an air conditioning system; a heat exchanger in a solar heat system; a heat exchanger in circulating grates of a fire place system; a heat exchanger in or about the stack for flue gas etc.